Abdellatif Kechiche’s “Blue is the Warmest Color” is often a study of facial landscapes. Specifically, that of Adele Exarchopoulos, whose performance is one of great ambiguity. She’s the subject of countless close-ups, raw and real, without makeup, which would add a layer of contrivance to the performance.

Her character, also named Adele, is confused and lost at the beginning of the film, and still confused and lost when the credits roll three hours later, several years later in narrative time. Such is life. Adele only experiences clarity and certainty while in the throes of passion with her lover, Emma (Lea Seydoux). They devour each other body and soul during drawn-out lovemaking sequences that are, shall we say, rather European in aesthetic. Although some might find them excessive, they aren’t purposeless – the point is to show how moments of ecstasy and grief are inextricably tied to deep, intimate relationships. Kechiche’s message? Love is extreme.

However, the most striking image in my memory isn’t the graphic sex, but a close-up two-shot of the couple’s faces, where Emma’s crystal-blue eyes are a burst of laser color against a backdrop of pallid skin and white sheets. As the title suggests, blue is a visual motif throughout the film, and it has classically symbolized both tranquility and sadness – more ambiguity. The first time Adele feels homosexual attraction is when she sees the openly gay Emma and her dyed-blue hair, in passing, on the street. The first girl to kiss Adele has chipped blue nail polish. At the end of the movie, Adele wears a blue dress. (Notably, the French title of the film is “La Vie d’Adele,” “The Life of Adele,” but the English-language title feels like the median between that and the source material, Julie Maroh’s graphic novel “Blue Angel.”)

Kechiche reportedly filmed Exarchopoulos in her daily life, while eating, sleeping, taking the train. It’s an extreme measure to take in the quest for naturalism, but it works. It has a hint of voyeurism, making the dramatic and mundane moments bracingly real. The consistency of Exarchopoulos’ performance makes her characterization all the more astonishing. She's extraordinary.

The story begins when Adele is 17, in high school. She meets a sweet classmate named Samir (Salim Kechiouche), and sleeps with him. But post-coitus, she has an empty look on her face, of dissatisfaction and fear. She hurts him, as she must. Adele finds some clarity when the blue-nail-polish girl kisses her. Her closest confidant is Valentin (Sandor Funtek), who takes her to a gay bar, where she catches Emma’s eye. He also rescues her from a cruel inquisition by a gallery of her peers. In such moments, “Blue is the Warmest Color” finds great dramatic focus, and we feel intense heartbreak as Adele’s crisis of sexual identity is made public.

Kechiche veers wildly from the suggestive and evocative to the explicit, which isn’t limited to bedroom entanglements. He eavesdrops on Adele’s lit-class lectures, and contrives to offer profound angles on her situation – big-picture lessons on love, tragedy, sin. The film is best when he ties visual detail into the development of Adele’s character. Emma, a budding artist, draws Adele, and the scratchy, indefinite lines of the sketch show a woman in the process of finding herself. Later, Adele poses nude for one of Emma’s paintings, and the picture is fuller, bolder, but still enigmatic in identity.

The film follows their relationship over several years. They move in together, and establish careers, Emma as an artist, Adele as a preschool teacher. Emma’s parents introduce Adele to the joys of eating oysters. Adele prefers to keep her homosexuality hidden from her parents, and the couple concocts a ruse to keep them in the dark. Their story is episodic and indulgent, yet compelling. It moves quickly. Its most consistent element is Kechiche’s fascination with Exarchopoulos’ face, so subtly expressive, it’s art in motion.

John Serba is film critic and entertainment reporter for MLive and The Grand Rapids Press. Email him at jserba@mlive.com or follow him on Twitter or Facebook.